This has been common in the US this summer, and that's what happened in my location. We received around 7" of rain in 4 hours. My basin was labeled as a 1 in 300 year flood; others nearby were 1 in 1500 years.

This happened again in 2 location in the US: Missouri and South Carolina.

A disturbance stalled over Missouri this morning, dropping between 7 and 11 inches of rain in 5 hours. (First picture)

On a more localized level like in Maryland, the eastern side of Columbia SC picked up 4.64" in 90 minutes.

Upper level winds have been slow this summer abnormally. In addition, it has been slightly more moist (higher dew points) than usual. More scattered storms, and more moisture to work with this summer than normal.

There was another instance of very isolated heavy rainfall totals, this time in North Carolina, where area near Mt. Airy, North Carolina (Near the Virginia border) saw between 8 and 10 inches of rain in a few hours. Just a few miles away, less than 1/2" of rain fell. Image from Chief Meteorologist Brad Panovich in North Carolina.

People usually become happy when the rain starts but too heavy rain can lead to floods and landslidings. Even the recent hurricane Mathew, caused flood in some of the cities. Too heavy rain could cause destruction to the property and it could also be life threatening.